Further to Malcolm Taylor’s letter (10 December, page 29), it may well be puzzling that the services element of a building does not receive the same level of prescriptive design as the architectural elements.

However, that does not prevent us from understanding the systems to be installed and the aspirations of the client and design team in respect of what that system is to achieve. Component costs are as readily available for heating, lighting and ventilation as they are for foundations, facades and floors. The trick is to identify the main cost drivers in any project and question the design team on their intentions in order to formulate a clear description of the component parts of the building.

By all means let us have a debate, but we must not lose sight of the continuing need to improve the cost forecasting at all levels within building services.

Jim Crouch, via email